Described below are a cellulose material provided with an impregnation that increases the electrical conductivity of the cellulose material and a use of this cellulose material.
U.S. Pat. No. 4,521,450 discloses that an impregnable solid material composed of cellulose fibers can be dipped into an aqueous oxidizing agent, for example a weakly acidic solution of iron(III) chloride solution, cerium(IV) sulfate, potassium hexacyanoferrate(III) or molybdophosphoric acid. Subsequently, the moist cellulose material is treated either with liquid or vaporous pyrrole compounds at room temperature until the pyrrole is polymerized, depending on the concentration of the oxidizing agent. The cellulose material thus impregnated is dried at room temperature for 24 hours. The oxidizing agent firstly ensures the polymerization of the pyrrole compounds, and also an increase in the electrical conductivity. The specific resistivity p of such impregnated cellulose materials can thus be influenced via the concentration of pyrroles and the type of oxidizing agent. In the production of the impregnated cellulose material, the toxic effect of pyrrole has to be taken into account through suitable working conditions and appropriate waste disposal.
In general, the use of electrically conductive polymers is known, for example, from DE 10 2007 018 540 A1, in order to use transparent, electrically conductive layers, for example, for the heating of automotive glass. Examples of such electrically conductive polymers are polypyrroles, polyaniline, polythiophenes, polyparaphenylenes, polyparaphenylene-vinylenes and derivatives of the polymers. A specific example of such polymers is PEDOT, which is also sold under the Baytron trade name by Bayer AG. PEDOT is also referred to by its systematic name of poly(3,4-ethylenedioxy-thiophene).